I made the two lines below with the pen tool. Fairly easy. But what i would like to do is combine them to make a kind of wave. ( I dont believe the wave or zig zag filter will do what i want, i have tried it).

I want the above image to look like the one below, ( i highlighted the area in black)

Ultimately i am trying to make something similar to that image on the bottom. It is the letter A and the letter W combined into a single character. I am having alot of trouble with it though and i want it to be precise, not hand drawn with the blog tool or pencil, it looks too cartooney.

Yu can do this with the pen tool without the need to combine the lines

You start bey clicking with the pen tool and dragging upward then with the smart guides on you move the pen tool a distance you want the first wave to be and click and drag downward hold the shift key after you start drag to restrain the angle of the drag to 90º.

Then while the path is still selected place the pen too at a distance where want the return path to start the next wave and drg upward

Then place the pen tool while the path is still selected at the distance you want the wave to be

and so on. You can extend the ends of the paths by either select it with the direct select tool and dragging it downward or you can place the pen tool where you wan the path to extend to and clicking and then click the pen tool at the end of the existing path that will add to the path.

I tis best you do a search for a tutorial on how to use the ten tool and or purchase Mordy Golding's book Real World Illustrator CS(#)

Mordy has a way of writing about software that is extremely clear and very user friendly I had a lot of difficulties with Illustrator until I read a few passages written by Mordy that clarified the program for me.

You can then add a different stroke width or brush. When drawing a precision path I often use a thin stroke and ad to itlater.

This works, but it doesnt answer my question fully. I need the curve to start heading upwards before it goes below the bottom of the first curve... if that makes sense. The design has a bottom to it, and that bottom is the opening of the first arch. In your example you make the second arch go below the "horizon" or whatever you want to call the bottom of the first arch. haha, there has to be a graphical term for that, but oh well. Thanks for the advice.

See the hard black line? That would be the bottom of the image. The curve cant go below that. I got these results with the scissors tool, which is closer to what i needed. I just need to do the same thing about 2-3 more times and then start changing the height of the arches and I think i will have a good base.

Depending on the desired regularity of the shape, you may create a more hand drawn appearance by creating one path with the Pen Tool, or you may create a highly symmetrical/regular one by using repetition of basically identical path segments. I understood from the OP that you wanted a high degree of regularity, based on the latter.

If that is the case, one extreme way is to use one path segment and repeat it by scaling, reflecting and rotating, with editing according to need and wish.

The swiftly made samples below are based upon the segment to the top left with just two Anchor Points, scaled to one half and one quarter, with and without the joining shown in the first two AWs, which have a swing to end the symmetrical W. In the third AW, the rightmost part of the W is identical to the leftmost part of the A (thin original), and scaled to 5/8; and shown over the leftmost part of the W (thin). In the fourth AW, the leftmost segment of the A is scaled to 3/4 (thin original).